US20080306907A1 - Redundant version information in history table that enables efficient snapshot querying - Google Patents

Redundant version information in history table that enables efficient snapshot querying Download PDF

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US20080306907A1
US20080306907A1 US12194540 US19454008A US2008306907A1 US 20080306907 A1 US20080306907 A1 US 20080306907A1 US 12194540 US12194540 US 12194540 US 19454008 A US19454008 A US 19454008A US 2008306907 A1 US2008306907 A1 US 2008306907A1
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version
row
value
data
history table
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US12194540
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US8010492B2 (en )
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Dilip Kumar BISWAL
Isaac Kam-Chak Cheng
Cecilia O. Chu
Donald Lee Clare
Louis S.W. Mau
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International Business Machines Corp
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International Business Machines Corp
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    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F17/00Digital computing or data processing equipment or methods, specially adapted for specific functions
    • G06F17/30Information retrieval; Database structures therefor ; File system structures therefor
    • G06F17/30286Information retrieval; Database structures therefor ; File system structures therefor in structured data stores
    • G06F17/30289Database design, administration or maintenance
    • G06F17/30309Managing data history or versioning
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F17/00Digital computing or data processing equipment or methods, specially adapted for specific functions
    • G06F17/30Information retrieval; Database structures therefor ; File system structures therefor
    • G06F17/30286Information retrieval; Database structures therefor ; File system structures therefor in structured data stores
    • G06F17/30345Update requests
    • G06F17/30348Concurrency control
    • G06F17/30351Optimistic concurrency control
    • G06F17/30356Optimistic concurrency control using versioning
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06FELECTRIC DIGITAL DATA PROCESSING
    • G06F17/00Digital computing or data processing equipment or methods, specially adapted for specific functions
    • G06F17/30Information retrieval; Database structures therefor ; File system structures therefor
    • G06F17/30286Information retrieval; Database structures therefor ; File system structures therefor in structured data stores
    • G06F17/30345Update requests
    • G06F17/30348Concurrency control
    • G06F17/30351Optimistic concurrency control
    • G06F17/30353Optimistic concurrency control using timestamps
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S707/00Data processing: database and file management or data structures
    • Y10S707/99931Database or file accessing
    • Y10S707/99932Access augmentation or optimizing
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S707/00Data processing: database and file management or data structures
    • Y10S707/99931Database or file accessing
    • Y10S707/99933Query processing, i.e. searching
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S707/00Data processing: database and file management or data structures
    • Y10S707/99951File or database maintenance
    • Y10S707/99952Coherency, e.g. same view to multiple users
    • Y10S707/99953Recoverability

Abstract

A system for efficient snapshot querying include: providing a first version value for each data in a history table, where the first version value indicates a beginning of a period in which the data is valid; providing at least a second version value for each data in the history table, where the second version value indicates an end of the period in which the data is valid; receiving a request for a version of a database; and retrieving the data with the first version value less than or equal to the requested version and the second version value greater than or equal to the requested version. By maintaining a history table with redundant version information, the system is able to provide efficient snapshot querying while also avoiding the overhead burden of conventional approaches. No aggregates, joins, or sub-queries are required to retrieve a snapshot.

Description

    CROSS-REFERENCE TO RELATED APPLICATIONS
  • Under 35 USC §120, this application is a continuation application and claims the benefit of priority to U.S. patent application Ser. No. 11/039,528 filed Jan. 19, 2007, entitled “REDUNDANT VERSION INFORMATION IN HISTORY TABLE THAT ENABLES EFFICIENT SNAPSHOT QUERYING”, all of which is incorporated herein by reference.
  • FIELD OF THE INVENTION
  • The present invention relates to data retrieval and more particularly to snapshot querying of a database.
  • BACKGROUND OF THE INVENTION
  • The need to retrieve snapshots of a table in a database is known in the art. The requested snapshot may be of a previous version of the table. Several conventional approaches exist for retrieving such a snapshot. A first conventional approach periodically backs up the entire database. The entire database is then restored to retrieve the snapshot of each table in the database. A second conventional approach periodically creates static tables. When creating a static table, all the data from a dynamic table is copied into a static table. After the copying finishes, the static table becomes a snapshot of the dynamic table. However, these approaches require burdensome overhead during the creation and deletion of snapshots and thus is not practical for mobile database applications.
  • A third conventional approach maintains a history table with a single version or timestamp associated with each historical value of each row in a dynamic table. FIG. 1 illustrates this third conventional approach. Version 1 illustrates two entries in table T with keys ‘1’ and ‘2’. The history table HT maintains a single version value associated with each historical value for keys ‘1’ and ‘2’. The ‘is Deleted’ column indicates whether the row was deleted in the indicated version. In version 2, the value of the row with key ‘2’ is changed from ‘20’ to ‘8’. A new row is added to the history table with the version value ‘2’. In version 3, the data value with key ‘1’ is changed from ‘10’ to ‘6’. A new row is added to the history table with version value ‘3’. However, to properly retrieve a snapshot of the table T at version 2, a query with aggregates, joins, and sub-queries is required:
  • SELECT key, data FROM HT wanted WHERE isDeleted = false AND
    (wanted.version = 2 OR wanted.version=(SELECT MAX(lessThanWanted.version)
    FROM HT
    lessThanWanted
    WHERE lessThanWanted.version<=2 AND lessThanWanted.key=wanted.key))
  • Such a query requires considerable processing resources and is thus an inefficient approach.
  • Accordingly, there exists a need for a system for efficient snapshot querying. The system should be able to retrieve a snapshot without requiring a query with aggregates, joins, or sub-queries. It should also significantly reduce overhead requirements. The present invention addresses such a need.
  • SUMMARY OF THE INVENTION
  • A system for efficient snapshot querying include: providing a first version value for each data in a history table, where the first version value indicates a beginning of a period in which the data is valid; providing at least a second version value for each data in the history table, where the second version value indicates an end of the period in which the data is valid; receiving a request for a version of a database; and retrieving the data with the first version value less than or equal to the requested version and the second version value greater than or equal to the requested version. By maintaining a history table with redundant version information, the system is able to provide efficient snapshot querying while also avoiding the overhead burden of conventional approaches. No aggregates, joins, or sub-queries are required to retrieve a snapshot.
  • BRIEF DESCRIPTION OF THE FIGURES
  • FIG. 1 illustrates a conventional approach to snapshot querying.
  • FIG. 2 illustrates an embodiment of a system for efficient snapshot querying in accordance with the present invention.
  • FIG. 3 is a flowchart illustrating an embodiment of the method for efficient snapshot querying in accordance with the present invention.
  • FIG. 4 illustrates an example snapshot querying in accordance with the present invention.
  • FIG. 5 illustrates the example set forth in FIG. 4 with version values indexed and sorted.
  • FIG. 6 is a flowchart illustrating the maintenance of the history table in accordance with the present invention.
  • FIGS. 7 through 9 illustrate examples of the maintenance of the history table in accordance with the present invention.
  • DETAILED DESCRIPTION
  • The present invention provides a system for efficient snapshot querying. The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the preferred embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiment shown but is to be accorded the widest scope consistent with the principles and features described herein.
  • To more particularly describe the features of the present invention, please refer to FIGS. 2 through 9 in conjunction with the discussion below.
  • FIG. 2 illustrates an embodiment of a system for efficient snapshot querying in accordance with the present invention. The system includes a server 201 or anything that stores data and a device 205 that stores a subset of the data stored on the server 201. Occasionally, the device 205 connects to the server 201 to synchronize its copy of the subset with that stored at the server 201. The subset is defined by a filter 204. The server 201 is capable of determining a pre-image 202 of the data on the device 205 after a previous synchronization. During a current synchronization, the server 201 determines the current image 203 of the data according to the filter 204, i.e., the data the device 205 should have after the synchronization. Next, the server 201 determines a delta of the current image 203, where the delta includes data that changed since the previous synchronization and that exists in the current image 203. The server 201 then instructs the device 205 to delete the data that exists in the pre-image 202 but not in the current image 203. The server 201 further instructs the device 205 to UPSERT the union of the data that exists in the delta and the data that exists in the current image 203 but not in the pre-image 202. The UPSERT operation is an operation on a row (R) to a target table (T) with the following properties: 1. Before performing the UPSERT operation, if R is already in T, the UPSERT operation is logically equivalent to an SQL UPDATE operation. 2. Before performing the UPSERT operation, if R is not in T, the UPSERT operation is logically equivalent to an SQL INSERT operation.
  • Although the present invention is described in the context of the system illustrated in FIG. 2, one of ordinary skill in the art will understand that the present invention can be applied to other types of systems without departing from the spirit and scope of the present invention.
  • Important to the calculation of the pre-image 202 is the retrieval of a snapshot of the data in the database tables. FIG. 3 is a flowchart illustrating an embodiment of the method for efficient snapshot querying in accordance with the present invention. First, a first version value for each data in a history table is provided, where the first version value indicates a beginning of a period in which the data is valid, via step 301. The history table is maintained at the server 201. Also, at least a second version value is provided for each data in the history table, where the second version value indicates an end of the period in which the data is valid, via step 302. Optionally, more than two version values can be used. When a request for a version of a database is received, via step 303, the data retrieved is that which has a first version value less than or equal to the requested version and a second version value greater than or equal to the requested version, via step 304.
  • FIG. 4 illustrates an example data table, T, and its corresponding history table, HT. Version 1 includes data values ‘10’ and ‘20’ with keys ‘1’ and ‘2’, respectively. In the history table, each data value has a corresponding first version value, ‘from’, and a corresponding second version value, ‘to’. In version 1, the ‘from’ value is ‘1’ for both data values ‘10’ and ‘20’. Their ‘to’ values are set to an adequately large value, denoted here symbolically by infinity.
  • In version 2, the data value in table T with key ‘2’ is changed from ‘20’ to ‘8’. A new row is then added to the history table for key ‘2’. The first version value, ‘from’, for this data value is set to ‘2’, via step 301, and the second version value, ‘to’, is set to infinity, via step 302. The ‘to’ value for the old data value for key ‘2’ is also changed to ‘1’. In this manner, the version values for the old data value ‘20’ indicate that the old data value is valid from version 1 to version 1, i.e., only for version 1. The version values for the new data value ‘8’ indicate that the new data value is valid from version 2 onward.
  • In version 3, the data value in table T with key ‘1’ is changed from ‘10’ to ‘6’. A new row is then added to the history table for key ‘1’. The ‘from’ value for this data value is set to ‘3’, via step 301, and the ‘to’ value is set to infinity, via step 302. The ‘to’ value for the old data value ‘10’ is also changed to ‘2’. In this manner, the version values for the old data value ‘10’ indicate that the old data value is valid from version 1 to version 2. The version values for the new data value ‘6’ indicate that the new data value is valid from version 3 onward.
  • Assume that server 201 then receives a request for version 2 of the database, via step 303. The rows {1, 10, 1, 2} and {2, 8, 2, ∞} have ‘from’ values <=2 and ‘to’ values >=2. The data values ‘10’ and ‘8’ (and their corresponding keys) are then retrieved, via step 304. The query required for retrieving this snapshot is as follows:
  • SELECT key, data FROM HT WHERE is Deleted=false AND from<=2 AND 2<=to
  • Unlike the conventional approach, no aggregates, joins, or sub-queries are required to retrieve the snapshot. Thus, by maintaining a history table with redundant version information as described above, the method and system in accordance with the present invention are able to provide efficient snapshot querying while also avoiding the overhead burden of conventional approaches.
  • To further improve the efficiency of the snapshot querying, index scanning can be used in the retrieval of the snapshot. FIG. 5 illustrates the example set forth in FIG. 4 with the ‘from’ and ‘to’ version values indexed and sorted. Because the ‘from’ version value is indexed, the entries in the history table can be sorted accordingly and only the left bracketed rows need to be scanned. Similarly, because the ‘to’ version value is indexed, the entries in the history table can be sorted accordingly and only the right bracketed rows need to be scanned. The resulting bitmaps of the two index scans are then combined using a bitwise AND operation to obtain the final result.
  • FIG. 6 is a flowchart illustrating the maintenance of the history table in accordance with the present invention. With each change to a row in the data table, a row is added to the history table, via step 601. The ‘from’ version value of the added row is then set to the current version, via step 602, and the ‘to’ version value is set to infinity, via step 603. If the operation on the data table is a row insert, then the ‘is Deleted’ value for the added row is set to ‘false’, via step 605. If the operation is a row delete, then the ‘is Deleted’ value for the added row is set to ‘true’, via step 606, and the old row is modified by setting the ‘to’ version value to the previous version, via step 607. Here, the old row is the row in the history table with the same key and with a ‘to’ version value of infinity. If the operation is a row update, then the ‘is Deleted’ value for the added row is set to ‘false’, via step 608, and the old row is modified by setting the ‘to’ version value to the previous version, via step 609.
  • For example, FIG. 7 illustrates a row insert in accordance with the present invention. Here, the previous version is version ‘3’. A new row is inserted into the data table, T, with key ‘3’ and data value ‘30’. This change to table T occurs when the value of the version is ‘4’. A row is then added to the history table, HT, via step 601. For this added row, the key is ‘3’ and the data value is ‘30’. The ‘from’ version value is set to the current version ‘4’, via step 602, the ‘to’ version value is set to infinity, via step 603, and the ‘is Deleted’ value is set to ‘false’, via step 605. The added row thus indicates that the row with key ‘3’ and data value ‘30’ is valid from version 4 onward.
  • Referring to FIG. 8, assume that next, the row with key ‘1’ and data value ‘6’ is deleted from table T. Here, the previous version is ‘4’, and the current version is ‘5’. A row is then added to the history table, via step 601. For this added row, the key is ‘1’ with no data value. The ‘from’ version value is set to the current version ‘5’, via step 602, and the ‘to’ version value is set to infinity, via step 603. Also, the ‘is Deleted’ value is set to ‘true’, via step 606, and the old row in the history table (with key=‘1’ and data value=‘6’) is modified by setting the ‘to’ version value to the previous version ‘4’, via step 607. The added row thus indicates that the row in table T with key ‘1’ was deleted in version 5 and is not in table T from version 5 onward. The modified old row in the history table indicates that the row in table T with key ‘1’ and data value ‘6’ is valid from version 3 to version 4.
  • Referring to FIG. 9, assume that next, the row in table T with key ‘3’ and data value ‘30’ is updated to data value ‘888’. Here, the previous version is ‘5’, and the current version is ‘6’. A row is then added to the history table, via step 601. For this added row, the key is ‘3’ and the data value is ‘888’. The ‘from’ version value is set to the current version ‘6’, via step 602, and the ‘to’ version value is set to infinity, via step 603. Also, the ‘is Deleted’ value is set to ‘false’, via step 608, and the old row in the history table (with key=‘3’ and data value=‘30’) is modified by setting the ‘to’ version value to the previous version ‘5’, via step 609. The added row in the history table thus indicates that the row in table T with key ‘3’ and data value ‘888’ is valid from version 6 onward. The modified row in the history table indicates that the row in table T with key ‘3’ and data value ‘30’ is valid from version 4 to version 5. The snapshot of any version can then be retrieved as described above.
  • A method and system for efficient snapshot querying have been disclosed. By maintaining a history table with redundant version information, the method and system are able to provide efficient snapshot querying while also avoiding the overhead burden of conventional approaches. No aggregates, joins, or sub-queries are required to retrieve a snapshot.
  • Although the present invention has been described in accordance with the embodiments shown, one of ordinary skill in the art will readily recognize that there could be variations to the embodiments and those variations would be within the spirit and scope of the present invention. Accordingly, many modifications may be made by one of ordinary skill in the art without departing from the spirit and scope of the appended claims.

Claims (16)

  1. 1. A system to query for a database snapshot with more than one version without requiring a query having aggregates, joins, and sub-queries, comprising:
    a database comprising a data table and a history table having redundant version information, wherein for each change to the data table, a row is added to the history table; and
    means for maintaining the history table, wherein the maintaining comprises:
    providing a first version value for the added row in the history table, wherein the first version value indicates a beginning of a period in which a data value of the added row is valid, and
    providing at least a second version value for the added row in the history table, wherein the second version value indicates an end of the period in which the data value of the added row is valid,
    wherein when a request for a version of the database is received, the data values with the first version value less than or equal to the requested version and the second version value greater than or equal to the requested version are retrieved from the history table.
  2. 2. The system of claim 1, wherein the mean_for maintaining:
    determines that a change in a row in the data table has occurred; and
    adds the row to the history table corresponding to the changed row, wherein the adding comprises:
    setting the first version value for the added row to a current version, and
    setting the second version value for the added row to a significantly large number.
  3. 3. The system of claim 2, wherein the means_for maintaining:
    determines that the change is a row insert; and
    sets a delete Boolean value for the added row to ‘false’.
  4. 4. The system of claim 2, wherein the means for maintaining:
    determines that the change is a row delete;
    sets a delete Boolean value for the added row to ‘true’; and
    modifies an old row in the history table for a key of the changed row in the data table by changing its second version value to a previous version.
  5. 5. The system of claim 2, wherein the means for maintaining:
    determines that the change is a row update;
    sets a delete Boolean value for the added row to ‘false; and
    modifies an old row in the history table for a key of the changed row in the data table by changing its second version value to a previous version.
  6. 6. The system of claim 1, wherein the means for maintaining:
    performing a first scan of rows in the history table for rows with the first version value less than or equal to the requested version;
    performing a second scan of rows in the history table for rows with the second version value greater than or equal to the requested version; and
    determining an intersection of the first and second scans.
  7. 7. The system of claim 6, wherein the first and second scans are indexed scans.
  8. 8. The system of claim 1, wherein the retrieved data each has a delete Boolean value of ‘false’.
  9. 9. A computer readable medium with program instructions for querying for a database snapshot with more than one version without requiring a query having aggregates, joins, and sub-queries, comprising:
    providing a first version value for each data in a history table having redundant version information, wherein the first version value indicates a beginning of a period in which the data is valid;
    providing at least a second version value for each data in the history table, wherein the second version value indicates an end of the period in which the data is valid;
    receiving a request for a version of a database; and
    retrieving the data with the first version value less than or equal to the requested version and the second version value greater than or equal to the requested version.
  10. 10. The medium of claim 9, further comprising:
    determining that a change in a row in the database has occurred; and
    adding a row to the history table corresponding to the changed row, wherein the adding comprises:
    setting the first version value for the added row to a current version, and
    setting the second version value for the added row to a significantly large number.
  11. 11. The medium of claim 10, wherein the adding further comprises:
    determining that the change is a row insert; and
    setting a delete Boolean value for the added row to ‘false’.
  12. 12. The medium of claim 10, wherein the adding further comprises:
    determining that the change is a row delete;
    setting a delete Boolean value for the added row to ‘true’; and
    modifying an old row in the history table for a key of the changed row by changing its second version value to a previous version.
  13. 13. The medium of claim 10, wherein the adding further comprises:
    determining that the change is a row update;
    setting a delete Boolean value for the added row to ‘false; and
    modifying an old row in the history table for a key of the changed row by changing its second version value to a previous version.
  14. 14. The medium of claim 9, wherein the retrieving comprises:
    performing a first scan of rows in the history table for rows with the first version value less than or equal to the requested version;
    performing a second scan of rows in the history table for rows with the second version value greater than or equal to the requested version; and
    determining an intersection of the first and second scans.
  15. 15. The medium of claim 14, wherein the first and second scans are indexed scans.
  16. 16. The medium of claim 9, wherein the retrieved data each has a delete Boolean value of ‘false’.
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Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070156985A1 (en) * 2005-12-30 2007-07-05 Industrial Technology Research Institute Snapshot mechanism in a data processing system and method and apparatus thereof
US20100057788A1 (en) * 2008-08-29 2010-03-04 International Business Machines Corporation Method, system, and computer program product for implementing back up history cleanup operations for a database management system
US20100274768A1 (en) * 2009-04-23 2010-10-28 Microsoft Corporation De-duplication and completeness in multi-log based replication
US8255820B2 (en) 2009-06-09 2012-08-28 Skiff, Llc Electronic paper display device event tracking
US8671074B2 (en) 2010-04-12 2014-03-11 Microsoft Corporation Logical replication in clustered database system with adaptive cloning
CN103646096A (en) * 2013-12-18 2014-03-19 用友软件股份有限公司 Method and device for generating sub-queries through user configuration

Families Citing this family (24)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6961804B2 (en) * 2001-07-20 2005-11-01 International Business Machines Corporation Flexible techniques for associating cache memories with processors and main memory
US7707165B1 (en) * 2004-12-09 2010-04-27 Netapp, Inc. System and method for managing data versions in a file system
US8271452B2 (en) * 2006-06-12 2012-09-18 Rainstor Limited Method, system, and database archive for enhancing database archiving
US8732386B2 (en) 2008-03-20 2014-05-20 Sandisk Enterprise IP LLC. Sharing data fabric for coherent-distributed caching of multi-node shared-distributed flash memory
US7975109B2 (en) 2007-05-30 2011-07-05 Schooner Information Technology, Inc. System including a fine-grained memory and a less-fine-grained memory
US8229945B2 (en) 2008-03-20 2012-07-24 Schooner Information Technology, Inc. Scalable database management software on a cluster of nodes using a shared-distributed flash memory
US8290966B2 (en) * 2007-11-29 2012-10-16 Sap Aktiengesellschaft System and method for implementing a non-destructive tree filter
US20090319501A1 (en) * 2008-06-24 2009-12-24 Microsoft Corporation Translation of streaming queries into sql queries
JP5205164B2 (en) * 2008-07-29 2013-06-05 株式会社日立製作所 File system management apparatus and method
US9047351B2 (en) 2010-04-12 2015-06-02 Sandisk Enterprise Ip Llc Cluster of processing nodes with distributed global flash memory using commodity server technology
US9164554B2 (en) 2010-04-12 2015-10-20 Sandisk Enterprise Ip Llc Non-volatile solid-state storage system supporting high bandwidth and random access
US8725951B2 (en) 2010-04-12 2014-05-13 Sandisk Enterprise Ip Llc Efficient flash memory-based object store
US8868487B2 (en) 2010-04-12 2014-10-21 Sandisk Enterprise Ip Llc Event processing in a flash memory-based object store
US8694733B2 (en) 2011-01-03 2014-04-08 Sandisk Enterprise Ip Llc Slave consistency in a synchronous replication environment
US8856593B2 (en) 2010-04-12 2014-10-07 Sandisk Enterprise Ip Llc Failure recovery using consensus replication in a distributed flash memory system
US8666939B2 (en) 2010-06-28 2014-03-04 Sandisk Enterprise Ip Llc Approaches for the replication of write sets
US8589349B2 (en) 2010-06-30 2013-11-19 International Business Machines Corporation Tracking and viewing revision history on a section-by-section basis
US8874515B2 (en) 2011-04-11 2014-10-28 Sandisk Enterprise Ip Llc Low level object version tracking using non-volatile memory write generations
CA2834864A1 (en) * 2011-05-05 2012-11-08 Reversinglabs International Gmbh Database system and method
US20120330991A1 (en) 2011-06-24 2012-12-27 International Business Machines Corporation Context- And Version-Aware Facade For Database Queries
US9742860B2 (en) * 2012-02-28 2017-08-22 International Business Machines Corporation Bi-temporal key value cache system
US9135064B2 (en) 2012-03-07 2015-09-15 Sandisk Enterprise Ip Llc Fine grained adaptive throttling of background processes
US9619539B2 (en) * 2012-09-28 2017-04-11 Vmware, Inc. Automated document replication in a distributed computing system
US9304998B2 (en) * 2012-12-19 2016-04-05 Microsoft Technology Licensing, Llc Main-memory database checkpointing

Citations (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5623661A (en) * 1994-12-07 1997-04-22 International Business Machines Corp. System for and method of providing delta-versioning of the contents of PCTE file objects
US5675802A (en) * 1995-03-31 1997-10-07 Pure Atria Corporation Version control system for geographically distributed software development
US5870758A (en) * 1996-03-11 1999-02-09 Oracle Corporation Method and apparatus for providing isolation levels in a database system
US5870759A (en) * 1996-10-09 1999-02-09 Oracle Corporation System for synchronizing data between computers using a before-image of data
US5950210A (en) * 1996-01-29 1999-09-07 Nelson; Paul M. Database row version differentiation process
US5956731A (en) * 1997-04-23 1999-09-21 Oracle Corporation Sharing snapshots for consistent reads
US5956713A (en) * 1997-04-23 1999-09-21 Oracle Corporation Techniques for reducing the number of snapshots of a database
US5963959A (en) * 1997-05-30 1999-10-05 Oracle Corporation Fast refresh of snapshots
US5999931A (en) * 1997-10-17 1999-12-07 Lucent Technologies Inc. Concurrency control protocols for management of replicated data items in a distributed database system
US6092086A (en) * 1998-03-31 2000-07-18 Bmc Software System and method for handling backout processing during capture of changed data in an enterprise computer system
US6289335B1 (en) * 1997-06-23 2001-09-11 Oracle Corporation Fast refresh of snapshots containing subqueries
US6295541B1 (en) * 1997-12-16 2001-09-25 Starfish Software, Inc. System and methods for synchronizing two or more datasets
US20020029218A1 (en) * 1998-09-28 2002-03-07 Bentley Keith A. System, method and computer program product for collaborative engineering using component and file oriented tools
US6377960B1 (en) * 1999-07-26 2002-04-23 Microsoft Corporation Transactional configuration store and runtime versus administration isolation with version snapshots and aging
US6415299B1 (en) * 2000-04-12 2002-07-02 Unisys Corp. Method for merging versions of a model in an object oriented repository
US6460052B1 (en) * 1999-08-20 2002-10-01 Oracle Corporation Method and system for performing fine grain versioning
US20020174416A1 (en) * 2001-05-15 2002-11-21 International Business Machines Corporation Storing and restoring snapshots of a computer process
US20020178146A1 (en) * 2001-05-24 2002-11-28 International Business Machines Corporation System and method for selective object history retention
US6516327B1 (en) * 1998-12-24 2003-02-04 International Business Machines Corporation System and method for synchronizing data in multiple databases
US20030149702A1 (en) * 2002-02-05 2003-08-07 Compaq Information Technologies Group, L.P. Operational data store
US6631374B1 (en) * 2000-09-29 2003-10-07 Oracle Corp. System and method for providing fine-grained temporal database access
US6665815B1 (en) * 2000-06-22 2003-12-16 Hewlett-Packard Development Company, L.P. Physical incremental backup using snapshots
US20040010487A1 (en) * 2001-09-28 2004-01-15 Anand Prahlad System and method for generating and managing quick recovery volumes
US20040019614A1 (en) * 2002-07-24 2004-01-29 International Business Machines Corporation Mid-tier-based conflict resolution method and system usable for message synchronization and replication
US6799189B2 (en) * 2001-11-15 2004-09-28 Bmc Software, Inc. System and method for creating a series of online snapshots for recovery purposes
US20050086263A1 (en) * 2003-09-04 2005-04-21 Oracle International Corporation Self-managing performance statistics repository for databases
US20050131964A1 (en) * 2003-12-12 2005-06-16 Oracle International Corporation Object versioning
US20050144198A1 (en) * 1999-03-05 2005-06-30 Microsoft Corporation Versions and workspaces in an object repository
US20060101092A1 (en) * 2004-11-09 2006-05-11 Hitachi, Ltd. Computer system and method for managing file versions

Patent Citations (30)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5623661A (en) * 1994-12-07 1997-04-22 International Business Machines Corp. System for and method of providing delta-versioning of the contents of PCTE file objects
US5675802A (en) * 1995-03-31 1997-10-07 Pure Atria Corporation Version control system for geographically distributed software development
US5950210A (en) * 1996-01-29 1999-09-07 Nelson; Paul M. Database row version differentiation process
US5870758A (en) * 1996-03-11 1999-02-09 Oracle Corporation Method and apparatus for providing isolation levels in a database system
US5870759A (en) * 1996-10-09 1999-02-09 Oracle Corporation System for synchronizing data between computers using a before-image of data
US5956731A (en) * 1997-04-23 1999-09-21 Oracle Corporation Sharing snapshots for consistent reads
US5956713A (en) * 1997-04-23 1999-09-21 Oracle Corporation Techniques for reducing the number of snapshots of a database
US5963959A (en) * 1997-05-30 1999-10-05 Oracle Corporation Fast refresh of snapshots
US6289335B1 (en) * 1997-06-23 2001-09-11 Oracle Corporation Fast refresh of snapshots containing subqueries
US5999931A (en) * 1997-10-17 1999-12-07 Lucent Technologies Inc. Concurrency control protocols for management of replicated data items in a distributed database system
US6295541B1 (en) * 1997-12-16 2001-09-25 Starfish Software, Inc. System and methods for synchronizing two or more datasets
US6092086A (en) * 1998-03-31 2000-07-18 Bmc Software System and method for handling backout processing during capture of changed data in an enterprise computer system
US20020029218A1 (en) * 1998-09-28 2002-03-07 Bentley Keith A. System, method and computer program product for collaborative engineering using component and file oriented tools
US6516327B1 (en) * 1998-12-24 2003-02-04 International Business Machines Corporation System and method for synchronizing data in multiple databases
US20030131025A1 (en) * 1998-12-24 2003-07-10 Zondervan Quinton Yves System and method for synchronizing data in multiple databases
US20050144198A1 (en) * 1999-03-05 2005-06-30 Microsoft Corporation Versions and workspaces in an object repository
US6377960B1 (en) * 1999-07-26 2002-04-23 Microsoft Corporation Transactional configuration store and runtime versus administration isolation with version snapshots and aging
US6460052B1 (en) * 1999-08-20 2002-10-01 Oracle Corporation Method and system for performing fine grain versioning
US6415299B1 (en) * 2000-04-12 2002-07-02 Unisys Corp. Method for merging versions of a model in an object oriented repository
US6665815B1 (en) * 2000-06-22 2003-12-16 Hewlett-Packard Development Company, L.P. Physical incremental backup using snapshots
US6631374B1 (en) * 2000-09-29 2003-10-07 Oracle Corp. System and method for providing fine-grained temporal database access
US20020174416A1 (en) * 2001-05-15 2002-11-21 International Business Machines Corporation Storing and restoring snapshots of a computer process
US20020178146A1 (en) * 2001-05-24 2002-11-28 International Business Machines Corporation System and method for selective object history retention
US20040010487A1 (en) * 2001-09-28 2004-01-15 Anand Prahlad System and method for generating and managing quick recovery volumes
US6799189B2 (en) * 2001-11-15 2004-09-28 Bmc Software, Inc. System and method for creating a series of online snapshots for recovery purposes
US20030149702A1 (en) * 2002-02-05 2003-08-07 Compaq Information Technologies Group, L.P. Operational data store
US20040019614A1 (en) * 2002-07-24 2004-01-29 International Business Machines Corporation Mid-tier-based conflict resolution method and system usable for message synchronization and replication
US20050086263A1 (en) * 2003-09-04 2005-04-21 Oracle International Corporation Self-managing performance statistics repository for databases
US20050131964A1 (en) * 2003-12-12 2005-06-16 Oracle International Corporation Object versioning
US20060101092A1 (en) * 2004-11-09 2006-05-11 Hitachi, Ltd. Computer system and method for managing file versions

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20070156985A1 (en) * 2005-12-30 2007-07-05 Industrial Technology Research Institute Snapshot mechanism in a data processing system and method and apparatus thereof
US7882315B2 (en) * 2005-12-30 2011-02-01 Industrial Technology Research Institute Snapshot mechanism in a data processing system and method and apparatus thereof
US20100057788A1 (en) * 2008-08-29 2010-03-04 International Business Machines Corporation Method, system, and computer program product for implementing back up history cleanup operations for a database management system
US7958090B2 (en) * 2008-08-29 2011-06-07 International Business Machines Corporation Method, system, and computer program product for implementing back up history cleanup operations for a database management system
US20100274768A1 (en) * 2009-04-23 2010-10-28 Microsoft Corporation De-duplication and completeness in multi-log based replication
US8108343B2 (en) 2009-04-23 2012-01-31 Microsoft Corporation De-duplication and completeness in multi-log based replication
US8255820B2 (en) 2009-06-09 2012-08-28 Skiff, Llc Electronic paper display device event tracking
US8671074B2 (en) 2010-04-12 2014-03-11 Microsoft Corporation Logical replication in clustered database system with adaptive cloning
CN103646096A (en) * 2013-12-18 2014-03-19 用友软件股份有限公司 Method and device for generating sub-queries through user configuration

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